Schedule II - AMERCO and Consolidated Subsidiaries, Valuation and Qualifying Accounts (Details) - Amerco [Member] - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Allowance for doubtful accounts (deducted from trade receivable) [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	$ 496	$ 539	$ 585
Additions charged to cost and expenses	1,550	886	913
Additions charged to other accounts
Deductions	(1,497)	(929)	(959)
Balance at year end	549	496	539
Allowance for obsolescence (deducted from inventory) [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	5,329	2,050	1,597
Additions charged to cost and expenses		3,279	1,218
Additions charged to other accounts
Deductions	(3,007)		(765)
Balance at year end	2,322	5,329	2,050
Allowance for LIFO (deducted from inventory) [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	16,126	14,340	13,463
Additions charged to cost and expenses	2,861	1,786	877
Additions charged to other accounts
Deductions
Balance at year end	18,987	16,126	14,340
Allowance for probable losses (deducted from mortgage loans) [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	618	493	368
Additions charged to cost and expenses		125	125
Additions charged to other accounts
Deductions	(125)
Balance at year end	$ 493	$ 618	$ 493